It's our second annual science fiction power list, featuring the 20 most powerful people and teams in the world of science fiction. Yes, science fiction can wield great power. These are the people who take responsibility for that.

This is not a list of io9's "favorites," or a compendium of people we think should have power. With this list, we've tried to reflect as accurately as possible who the movers and shakers are in the worlds of science fiction - the people who can command a big budget, or get a creative project produced just by signing their name to it. These are people whose tastes are setting pop culture fashion, and inspiring imitators across the globe. They're wheeling and dealing, controlling the kinds of stories you'll be reading, watching, and playing for years to come.

In addition, the list is not in order of power. All of these people are powerful in different ways, often in different industries.

JJ AbramsLost. Star Trek. Fringe. At this point, media polymath JJ Abrams can do no wrong on television or at the movies. He's rebooted Star Trek with a flourish, and even though FOX show Fringe may be flagging in the ratings this year, it's still garnering critical praise. Next up for Abrams: Two linked sequels to Star Trek and an untitled scifi/spy comedy series.

James Cameron
Whether you love or hate Avatar, there's no denying Cameron knows how to make science fiction into a rich, technically sophisticated storytelling genre. And he can command a budget of nearly $400 million, which is what many estimate Avatar cost. Next up for Cameron: More Avatar, and more technical innovations.

Lady Gaga
Like Cameron, Lady Gaga is another polarizer: You hate her or you love her, but either way she's unavoidable. With videos supporting her two latest releases, The Fame and The Fame Monster, she crafted an image of herself as a pop creation whose alienness rivals that of 1970s-era David Bowie. Dressed in outfits that belong on another planet, playing piano from inside whirling silver rings, Lady Gaga made sci fashion into just plain fashion. Next up for Gaga: Touring, mostly without pants on.

David Howe
Though he got a lot of razzing for the Syfy rebranding campaign, Howe has brought the once-marginal SciFi Channel into the mainstream with Syfy's blend of paranormal reality shows like Ghost Hunters, top-rated miniseries (Tin Man), and attention-grabbing series like Stargate Universe and Warehouse 13. Under Howe's watch, Syfy's ratings have gone through the roof, and the channel is now among the top ten most-watched channels among men ages 18–54, and women ages 25–54. Next for Howe: Several new series, including the much-anticipated Battlestar Galactica prequel Caprica in spring.

Patrick Nielsen Hayden
Senior Editor and the Manager of Science Fiction at Tor Books, Nielsen Hayden is a kingmaker among American science fiction novelists. Under his watch, Tor has helped turn writers like Cory Doctorow, John Scalzi, and Jo Walton into award-winning superstars of the genre world. Plus it doesn't hurt that Tor is re-releasing the mega-selling Wheel Of Time series. Next for Nielsen Hayden: More award-winning books.

Diane Nelson
A longtime executive at Warner Bros, Nelson was recently named DC Entertainment President, where she's going to take on the task of shuttling promising comic book properties into Time Warner's other media divisions - mostly movies. With properties like Batman, Justice League, and Wonder Woman under her watchful eye, Nelson is poised to set the tone for next decade's most anticipated (and, for some, dreaded) comic book movies. Our favorite Nelson quote: "I prefer to be known as an executive rather than a girl." Next for Nelson: Superman and Wonder Woman movies.

Warren Ellis
Ellis has long been a favorite among discerning comic book fans who have made his books Transmetropolitan and Planetary into cult hits. And his work on countless Marvel titles, as well as his novel Crooked Little Vein, have made him a critical darling as well. But Ellis' power extends far beyond the comic book world, and into the realms of subterranean fashion, philosophy, and trendsetting. He runs a very popular blog that routinely breaks news on the pop trends and weird news that feed the creative imaginations of writers, artists, filmmakers and fans. Ellis is one of the science fiction world's most influential tastemakers and opinion shapers. Next for Ellis: The movie version of his comic book Red starts filming in January, starring Bruce Willis and Morgan Freeman.

Charlaine Harris
With her Sookie Stackhouse novels constantly on bestseller lists, and HBO's Sookie series True Blood a critical and audience hit, Harris is the queen of vampire fiction for adults. She's also a pioneer of the supernatural romance genre, which has propelled science fiction and urban fantasy stories into the hands of women - and helped turn fantastical genre fiction into a mainstream obsession. Next for Harris: Dead in the Family, a new Sookie Stackhouse novel, in May 2010.

Felicia Day
Day, creator of the cult hit web show The Guild, was the star of scifi's biggest web sensation to date: Dr. Horrible's Singalong Blog. Now she's crossing over into the mainstream, with roles on House, Dollhouse, and Lie To Me. Day proves that web celebrities can be just as powerful as TV celebrities. Next for Day: Appearing in some of the final episodes of Dollhouse next year; The Guild season 4.

Audrey Niffenegger
With her mega-selling novel The Time Traveler's Wife now a Hollywood movie, it's no wonder that Audrey Niffenegger got almost $5 million for her latest novel, Her Fearful Symmetry, which came out earlier this year. Next for Niffenegger: An art exhibit at Printworks Gallery in September, 2010, and a third novel, The Chinchilla Girl in Exile.

Alastair Reynolds
Joining the millionaire science fiction author club along with Niffenegger is Reynolds, a British author whose space operas have netted him prestigious awards and fans the world over. Last year, he signed an unprecedented 10-book deal with leading UK SF publisher Gollancz, for £1 million. Next for Reynolds: A three-book cycle that the UK Guardiandescribed as "an African-inflected trilogy charting how humanity might go on to conquer the solar system and the galaxy."

Peter Jackson and Fran Walsh
Jackson and Walsh have been writing and production partners on some of the biggest science fiction and fantasy epics of the last decade, including the Lord of the Rings trilogy. Now Jackson is putting some of his muscle behind young directors like District 9's Niell Blomkamp, and it's paying off nicely; Jackson and Walsh have also been working with Guillermo Del Toro on developing two forthcoming movies based on The Hobbit. Next for Jackson and Walsh: Producing The Hobbit movies; a possible miniseries based on Naomi Novik's dragon warfare series called Temeraire.

Michael Bay
Bay exploded his way into some of the biggest box office cash in history with the incomprehensible yet lucrative Transformers 2. Call him a mindless detonation-whore if you want, but Bay's a money-making golden boy in Hollywood right now. Next for Bay: Transformers 3, set for 2011 release.

Ridley Scott
After blowing everybody's minds with his original visions in 1970s and 80s science fiction classics Alien and Bladerunner, Scott turned his attention to other genres, making incredible flicks like Thelma and Louise and American Gangster. But last year, to our delight, he set his sights on science fiction again. Next for Scott: He's got a prequel to Alien in the works, as well as plans to adapt Joe Haldeman's The Forever War and early SF classic Brave New World to the big screen.

Kevin Feige
As President of Production at Marvel Studios, Feige will control the vertical, horizontal, and asskickital on your movie screens for quite some time. Having worked as a producer on hits like Iron Man and Fantastic Four, Feige will continue his reign at Marvel with more films based on Marvel's characters. Now that Disney is putting its considerable weight behind Marvel Studios, we can only hope that the asskicking will get awesomer, not cutesier. Next for Feige: Producing movie versions of Thor, The Avengers, Captain America, Ant-Man, Deathlok, and more.

Image Metrics
When it comes to making science fiction look awesome, it's important to credit the power of a great tool and the people who make it. Image Metrics is an FX software package used for creating facial animation (often with motion-capture technology) and effects mavens love it. It was used to create effects for Benjamin Button last year, and this year was used for Avatar and the videogame Assassin's Creed II. Next for Image Metrix: You'll be seeing effects created with the software in the film Splice.

Neville Page
The creature designer whose monsters are sometimes more memorable than the actors who fight them, Page created the Cloverfield creature, as well as working on character and creature design in Star Trek (yes, that was his weird red monster on the ice planet), Watchmen and Avatar. Not only are his monsters cool; they actually help advance the stories we see them in. Next for Page: He designed the suits in the forthcoming sequel to Tron.

Patrice Desilets and Jade Raymond
As Ubisoft videogame Assassin's Creed veers into science fictional territory, game designer Desilets finds himself heading up the creative team behind one of the most interesting, complex, and fun SF/F games of the past few years. As producer on Assassin's Creed and Assassin's Creed 2, Raymond helped popularize the games and made them accessible to a broader audience. Next for Desilets and Raymond: Desilets is at work on the next installment of Assassin's Creed; Raymond is heading up a brand-new Toronto Ubisoft office, where she says she'll work on AAA games.

Sam Worthington
Aussie actor Worthington came out of nowhere to helm two of the year's most anticipated science fiction epics: Terminator 4 (where many argued he was the only interesting character), and Avatar (where he proved he can act even when he's turned into a motion-captured animation). He's poised to be Hollywood's next big SF action star. Next for Worthington: Clash of the Titans; producing and starring in comic book flick Last Days of American Crime; possible Avatar sequel.

Zoe Saldana
After stealing the show in JJ Abrams' Star Trek and kicking major ass in Avatar, Saldana is on track to be the next Sigorney Weaver: Able to play smart believably, and able to throw down in highly physical, action-adventure roles. She leaves everyone wanting to see more of her brains and brawn. Next for Saldana: comic book flick The Losers; Star Trek sequels.